Lockstitch sewing machine



B. T. LEVEQUE. LOCKSTITCH SEWING MACHHXE Filed May 14, 1928 4 sheys-sheet 1 4 Sheets-Sheet 2 B. T. LEVEQUE Filed May" 14. 1928 LOCKSTITCH SEWING MACHINE Oct. 13, 1931.

Oct, 13, 1931. a. T. LEVEQUE 1,827,321

I LOCKSTITCH SEWINGjpMACHlFNE Filed may 14. 1928 '4 Sheets-Sheet 5 Oct. 13, 1931. B. T. LEVEQUE LOCKSTITCH SEWING MACHINE Filed May 14. 1928 4 Sheets-Sheet 4 BERNA-RDT. m nimum on WENHAM; M-AssAcHUsETT's,Assmnon;To -Lemme snena "MACHINERYCORPORATION; OF rM-Ensom NEW JERSEY; A ooP PonATIon-oE-nnw v A p-i 'cimnmmec m 14,

i Theinvention relates to 'lockstitch sewing machines and; isiherein disclosed as; enibodie' d i inia l'ockstitch 1.19m Sh sew n'ge'em n i V the McKaytype, n k

ThQ- bieQt-Q th nv b o k o'p owdew mechanism ffor supplya novel and improy inggneedle'thpeadffor the stitch forming opel -j fi n ic e ie n i nd; s mp e m de of 0193122111011 and, acts efliciently and cercte-iniy to,setthestitchamniform distance'into the W "dle loop yieldlnglyndow With tngtt eei we; tam the invention consists in thQP'I' OViSiOII Of mechanie nwhi'eh ectsft'o pull; theneedle'loop y1e1c1- ngl-yi on act withg the surfaceof [the Q I Lemon-mt for the; nextfs titch front-the supply, fiil'lflHYftOdiHlgW the loop; intoithe' surface a; regular; evenstitch is QQbt-aine di withf the dfii hfl in e n con sts in the-pnoyision a: thneadihandling meche nis'mhaving e g-mode of; opemtion snbstanitiaillyi as above; descri;bed which is pe trticula-Ely adapted; for F use in! 5st glockstiteh horn shoe sewing machine o fiz the type herein dis- I closed as embodying gthe;pnesent inventiorn' nnrangement owf pmzts *heneinafter, described' n V 1s drawn off from the supply fen the formai g 5 ,The several f'eatnres,o-the-inyention consist also) in] the -deV-iice;s combinations and and'cl'ai med," which together with the advantegestobe-pbteincd:thereby; willibe readily imdersteod by pne sk illed-e in the; art from the following: description; taken. in connection Withathe accompanying drawings; 1,

gelemtion of" a lockstitchhorn shoe'eseyving and associated parts ;-1Fig. 3, isvatrdetail View in front elevetiontoiiithe"takeup and thread lock mechanisms for. theneedle thread; Fig. 4 e is edema view-partly'in section: of the parts} i11nstratedin-Eig-.-3 Eigs. 5 and- 6 aredetail 'vieweof the two, coopergtting cam surfaces I iol eopemting the thread lock and, Figs; 7 L te-lo inclnsivetaneeomewhatdiegfna nmatical In. carryingyllout 'theli 'preee ntintention,

tan ce intfo' the uworili.

lan-seam. v

e he invention is ill locketitchahor ng shoe sewing machine more f l y de ibe in h pplicationiSenialNQ.,- 9

, 203,;filed February means are provided ffo'r i a 'wingme old n the Work a'gain't a threa, sion aftenwhich thread for he exi; s i elmsgdar'awn through v wthe te'nsion frontthe supply. ,Einally the inventoiins-L pending l nto-f contact with loop is drawn-flown a, predetermined amount a]: mechanism. which; has econstant throw and acts 15o'sitii elyq again a; thneed'; lock so 'thet the, stitch elwey s eetat ainnifo fm disz f h Inf'the illustratedlv cons'tnuction, a; take-npleirer, situated'. directly beneath the h'a'je of ther'ho'rn actsjdgaihst the l threadlock to draw'the loop fiomtheishu ttle partially doWn to the work l'eavingsufficient thread throne I side 'ofthe needle loop on. the

next succeeding fetitchzfl At gthis point the thread lock is? remo ed; asitheenew loop is passed "around the shuttle; the old; loop}? is drawn yieldihgly down 'to'thewworkrageiiist a thread tension 'until' 'the iresistance o'fiered V byfthejcontactofthe 100p withlthe workexceedsthe va'nrionnt of the tension when thre d drawn from lthe"supply, the old- :needlek loop ifests' on'the surface ofithe Work'end inlor der to complete the Vst1t-ch,v1t. 1s merely necessary to. pull the loj'op lclown ztjsmell amount which 1 willbe. constant. for-each stitch regefdlessbi the thickne'ss of; worktoiset thetloop 'ja.

nifonm disflancefintb-the ork." TO hQQOIIlhe ipl eslentconstrndtion, the e 1 "jsed eteplredeterlninedpoiht in the movement, of the; shuttle before the'loopi whichheszbeen takenifmniithe needle passes oveif the top oi theshiittleeogthatthe continnedfmovementz of the shuttleqdxiaws a. centain fixede'amonnt of threadf-fiionithe' pre- I I V ceding loop and; pun thfezloopii-nt'o thefwork j the req iired; aniountftof secnneanievenijegm Referring more specifically to the drawings, the machine column is indicated at 12 provided with a sewing head 14 in which are mounted the straight hook needle 16, the presser foot 18, the feed point 20, and the oscillating shuttle 22. The shuttle is actuated in timed relation tothe needle through connections from the needle actuating mechanism which parts, together with the presser foot, and feed point, are all driven from the horizontally situated sewing cam shaft 24 in the head of the machine which is in turn driven from the motor 26 in the base through the vertical shaft 28 and intermediate connections, as fullydescribed and illustrated in the above-mentioned application.

A work supporting. horn 30 is rotatably mounted on a support or base 32secured to the machine column and is provided with a whirl 34 which is driven in timed relation to the 'sewing cam shaft and the'instrumentalities mounted in the head through connections from the vertical drive shaft 28 which include the horizontal shaft 36, the intermeshing bevel gears 38 and 39, and the verwhich the whirl is driven by means of a crank pin mounted on a cam disk 52 which is secured to the end of the shaft 36. The crank pin 50 is connected by a link 54 to the central pivot 56 of thetoggle levers 58 and 60 which are connected respectively to the fixed pivot 62 and to one end of the take-up lever 48 whiehhas a fixed pivot 64. In order to permit the throw of the take-up lever 48 to be regulated in accordance with the thickness of the Work so that a sufiicient amount of thread will be left in the old loop to supply 1 one side of the new needle loop, the pivot 62 of the toggle lever 58, and the pivot 64 of the take-up lever are mounted on a bracket 66 which is pivotally mounted on a stud 68 fixed in the machine frame, and is secured to the stud bya binding bolt 70. An arm extending upwardly from the hub of the bracket and provided with a slot through which a set screw 72 extends into the frame affords additional means by which thebracket' may be adjusted and retained in position to give the desired amount of throw to the take-up lever.

Tofurther facilitate the handling of the needlethread, an auxiliary take-up is provided consisting of a lever 73 mounted on the take-up lever 48, provided with an-eye 75 through which the thread is passed. A

'- spring 77 stretched between the auxiliary inclusive.

take-up lever and a point on the take-up lever 48 tends to turn the auxiliary take-up lever about its pivot to take up slack thread. The movement of the lever in the opposite direction is limited by the engagement of the flange 81 formed on the lower end of the lever with the under side of the take-up lever 48.

The thread clamp is actuated to release the thread during the earlier part of the movement of the shuttle to permit new thread to be drawn off from the supply and is then closed at a predetermined point in the movement of the shuttle to set the stitch a uniform distance into. the work by means of mechanism which 82 on the machine frame'and the hub of the cam lever 78. To the other end of the shaft is secured a cam faced block 84 which is held in engagement with an opposing stationary cam faced block 86 by means of a spring 88 coiled aboutthe shaft between the camblock 84 and the machine frame. {When the cam roll 76 rides 011 to the high portion of the cam 74, the shaft 80 is rocked and moved axially against the pressure'ofthe spring 88 through the inter-connection of the cam faced blocks 84 and 86 to release the thread clamp, as illustrated in Figs. 3 and 4. l/Vhen the cam roll reaches the low portion of the cam, the pressure of'the spring '88 causes the shaft 80 to be rocked in the opposite direction by the contact of the cam blocks and the'shaft to be moved axially to close the'thread clamp. 1

The operation of the thread handling mechanism informing a stitch is indicated somewhat diagrammatically in Figs. 7 to 10, The needle loop is drawn down from the shuttle partially to the work by means of the take-up lever 48, enough thread being left in the old loop to provide thread for one side of the needle loop of the-next succeeding stitch, as shown in Fig. 7. The thread lock at this time is closed to insure that the loop is drawn down through the work to the required extent from the shuttle. 'As the needle is retracted to draw the new needle loop through the work, the remaining thread from the old loop is drawn around through the work, and the thread required for the other side of the needle loop is given up'by the retracting movement of thetake-up At this point in the operation illustrated in Fig. 8, the thread lock is open as the cam roll 76 rides on to the raised portion of the cam 74. As the loop is taken from the needle and carried around the shuttle, the old loop is drawn firmly down against the work until the resistanceoffered by the contact of the loop with and additional thread for the new loop is 2 'down to the workto leave suflicient thread mentoftheishuttle with the parts in the posi- V I f )5 tions shownin Fig.9 before it reaches the 7 limit of itsloop drawing stroke, soithat the precedinglloop is pulled "down va fpi edeter vmined amount against the thread, lock to set the stitch a uniform distance into the work, i

as illustrated in Fig. 10; v

Thenature and scope of theinvent on'haw ing been indicated, and one, embodiment thereof in a lockstitch hornishoe sewing I machine having been described," what is claimed iszf Y r I I 1. A lockstltch sewlng machlnehavlng, 1n

for one side of the needle loopon the next succeeding stitch, a shuttle acting to draw oil thread from the supply for the next stitch I and thereafter to set the stitch, a thread lock against which the stitch is set, and means point in the movement of the shuttle.

7 21A lockstitch sewing machine having, in '7 j combination, stitch forming and setting devices includinga hook needle,"athread' tenthrea di lock to set the stitch tance into the work.

uniformdis- ,5. "Alockstitch sewing machine having, in a A combination, stitch forming and settingfdevicesincluding' ahook needle, a thread tension, a thread look, a shuttle acting to pull on the preceding needle loop against the tension until the resistance offered by the loop exceeds the amount of tension, then, todraw ofi thread through the tension from the supply for the next stitchand to finally setthe stitch, and. means for'closin'g the thread lock at a predetermined point iinvthe' rotation of the shuttle'after thread has been drawn from the supply for the next stitch to cause the stitch vto be setiduring the con name; to this specification.

i' for closing the thread look at a predetermined sion, a take-up for drawing aloop ofneedle thread partially down to the work to permit the needle on the next succeeding stitch to 1 draw thread for one side of the needle loop from the preceding, loop," a shuttle' acting' upon the new loop first to draw. the old loop into contact with the work against the thread tension and thereafter to draw'ofi' thread from the supply for the'n'ext stitch, a thread lock against which the stitch is set, and means I for closing-the thread look at a predetermined pointin the movement of the shuttle.

'3. "A lockstitchshoesewing machine hav ing, incombination, stitchforming and setting devices including a hook needle, a thread tension, means for drawing down the needle loop against the tensionuntil the resistance oflered by contact of the loop withthework exceeds the amount; of the tension and for thereafterl'drawing oflhthread through the tension fromthe supply for the next stitch,

and a thread'lock} againstwhich the stitch is set. I s 1 'j 4, A lockstitch shoe sewing machine having, in combination, stitch forming andfsetting devices including a hook needle, a thread tension, means for drawing down the. needle loop against the tension until the resistance ofleredby contact of the loop with the work exceeds the amount of tension and for thereafter drawing off thread through the ten- .fsion from the supplyfor the nextstitch, a thread lock, andomea ns .for-pullingidown the loop a predetermined amount against the tinned. rotation of the shuttle. 3 Z i BERNARD T, LETVEQUEQ as 1 U 

